using System;
using System.Collections;
using System.Runtime.InteropServices;
using System.Text; 

namespace ToolHelp
{
    #region Process class
    /// <summary>
    /// Summary description for Process.
    /// </summary>
    public class Process
    {
        private string processName;
        private IntPtr handle;
        private int threadCount;
        private int baseAddress; 

        //default constructor
        public Process()
        {
        } 

        private Process(IntPtr id, string procname, int threadcount, int baseaddress)
        {    
            handle = id;
            processName = procname;
            threadCount = threadcount;
            baseAddress = baseaddress;
        } 

        //ToString implementation for ListBox binding
        public override string ToString()
        {
            return processName;
        } 

        public int BaseAddress
        {
            get
            {
                return baseAddress;
            }
        } 

        public int ThreadCount
        {
            get
            {
                return threadCount;
            }
        } 

        public IntPtr Handle
        {
            get
            {
                return handle;
            }
        } 

        public string ProcessName
        {
            get
            {
                return processName;
            }
        } 

        public int BaseAddess
        {
            get
            {
                return baseAddress;
            }
        } 

        public void Kill()
        {
            IntPtr hProcess;
            hProcess = OpenProcess(PROCESS_TERMINATE, false, (int) handle); 

            if(hProcess != (IntPtr) INVALID_HANDLE_VALUE) 
            {
                bool bRet;
                bRet = TerminateProcess(hProcess, 0);
                CloseHandle(hProcess);
            }

        } 

        public static Process[] GetProcesses()
        {
            ArrayList procList = new ArrayList(); 

            IntPtr handle = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0); 

            if ((int)handle > 0)
            {
                try
                {
                    PROCESSENTRY32 peCurrent;
                    PROCESSENTRY32 pe32 = new PROCESSENTRY32();
                    //Get byte array to pass to the API calls
                    byte[] peBytes = pe32.ToByteArray();
                    //Get the first process
                    int retval = Process32First(handle, peBytes); 

                    while(retval == 1)
                    {
                        //Convert bytes to the class
                        peCurrent = new PROCESSENTRY32(peBytes);
                        //New instance
                        Process proc = new Process(new IntPtr((int)peCurrent.PID), peCurrent.Name, (int)peCurrent.ThreadCount, (int)peCurrent.BaseAddress);
                        procList.Add(proc); 

                        retval = Process32Next(handle, peBytes);
                    }
                }
                catch(Exception ex)
                {
                    throw new Exception("Exception: " + ex.Message);
                }
                //Close handle
                CloseToolhelp32Snapshot(handle); 
                return (Process[])procList.ToArray(typeof(Process)); 

            }
            else
            {
                throw new Exception("Unable to create snapshot");
            } 

        } 

        #endregion 

        #region PROCESSENTRY32 implementation 

//        typedef struct tagPROCESSENTRY32 
//        { 
//            DWORD dwSize; 
//            DWORD cntUsage; 
//            DWORD th32ProcessID; 
//            DWORD th32DefaultHeapID; 
//            DWORD th32ModuleID; 
//            DWORD cntThreads; 
//            DWORD th32ParentProcessID; 
//            LONG pcPriClassBase; 
//            DWORD dwFlags; 
//            TCHAR szExeFile[MAX_PATH]; 
//            DWORD th32MemoryBase;
//            DWORD th32AccessKey;
//        } PROCESSENTRY32; 

        private class PROCESSENTRY32
        {
            // constants for structure definition
            private const int SizeOffset = 0;
            private const int UsageOffset = 4;
            private const int ProcessIDOffset=8;
            private const int DefaultHeapIDOffset = 12;
            private const int ModuleIDOffset = 16;
            private const int ThreadsOffset = 20;
            private const int ParentProcessIDOffset = 24;
            private const int PriClassBaseOffset = 28;
            private const int dwFlagsOffset = 32;
            private const int ExeFileOffset = 36;
            private const int MemoryBaseOffset = 556;
            private const int AccessKeyOffset = 560;
            private const int Size = 564;
            private const int MAX_PATH = 260; 

            // data members
            public uint dwSize; 
            public uint cntUsage; 
            public uint th32ProcessID; 
            public uint th32DefaultHeapID; 
            public uint th32ModuleID; 
            public uint cntThreads; 
            public uint th32ParentProcessID; 
            public long pcPriClassBase; 
            public uint dwFlags; 
            public string szExeFile;
            public uint th32MemoryBase;
            public uint th32AccessKey;
            //Default constructor
            public PROCESSENTRY32()
            { 

            } 

            // create a PROCESSENTRY instance based on a byte array        
            public PROCESSENTRY32(byte[] aData)
            {
                dwSize = GetUInt(aData, SizeOffset);
                cntUsage = GetUInt(aData, UsageOffset);
                th32ProcessID = GetUInt(aData, ProcessIDOffset);
                th32DefaultHeapID = GetUInt(aData, DefaultHeapIDOffset);
                th32ModuleID = GetUInt(aData, ModuleIDOffset);
                cntThreads = GetUInt(aData, ThreadsOffset);
                th32ParentProcessID = GetUInt(aData, ParentProcessIDOffset);
                pcPriClassBase = (long) GetUInt(aData, PriClassBaseOffset);
                dwFlags = GetUInt(aData, dwFlagsOffset);
                szExeFile = GetString(aData, ExeFileOffset, MAX_PATH);
                th32MemoryBase = GetUInt(aData, MemoryBaseOffset);
                th32AccessKey = GetUInt(aData, AccessKeyOffset);
            } 

            #region Helper conversion functions
            // utility:  get a uint from the byte array
            private static uint GetUInt(byte[] aData, int Offset)
            {
                return BitConverter.ToUInt32(aData, Offset);
            }
            // utility:  set a uint int the byte array
            private static void SetUInt(byte[] aData, int Offset, int Value)
            {
                byte[] buint = BitConverter.GetBytes(Value);
                Buffer.BlockCopy(buint, 0, aData, Offset, buint.Length);
            } 

            // utility:  get a ushort from the byte array
            private static ushort GetUShort(byte[] aData, int Offset)
            {
                return BitConverter.ToUInt16(aData, Offset);
            }
            // utility:  set a ushort int the byte array
            private static void SetUShort(byte[] aData, int Offset, int Value)
            {
                byte[] bushort = BitConverter.GetBytes((short)Value);
                Buffer.BlockCopy(bushort, 0, aData, Offset, bushort.Length);
            }
            // utility:  get a unicode string from the byte array
            private static string GetString(byte[] aData, int Offset, int Length)
            {
                String sReturn =  Encoding.Unicode.GetString(aData, Offset, Length);
                return sReturn;
            }
            // utility:  set a unicode string in the byte array
            private static void SetString(byte[] aData, int Offset, string Value)
            {
                byte[] arr = Encoding.ASCII.GetBytes(Value);
                Buffer.BlockCopy(arr, 0, aData, Offset, arr.Length);
            }
            #endregion 

            // create an initialized data array
            public byte[] ToByteArray()
            {
                byte[] aData;
                aData = new byte[Size];
                //set the Size member
                SetUInt(aData, SizeOffset, Size);
                return aData;
            } 

            public string Name
            {
                get
                {
                    return szExeFile.Substring(0, szExeFile.IndexOf('\0'));
                }
            } 

            public ulong PID
            {
                get
                {
                    return th32ProcessID;
                }
            } 

            public ulong BaseAddress
            {
                get
                {
                    return th32MemoryBase;
                }
            } 

            public ulong ThreadCount
            {
                get
                {
                    return cntThreads;
                }
            }
        }
        #endregion 

        #region PInvoke declarations
        private const int TH32CS_SNAPPROCESS = 0x00000002;
        [DllImport("toolhelp.dll")]
        public static extern IntPtr CreateToolhelp32Snapshot(uint flags, uint processid);
        [DllImport("toolhelp.dll")]
        public static extern int CloseToolhelp32Snapshot(IntPtr handle);
        [DllImport("toolhelp.dll")]
        public static extern int Process32First(IntPtr handle, byte[] pe);
        [DllImport("toolhelp.dll")]
        public static extern int Process32Next(IntPtr handle, byte[] pe);
        [DllImport("coredll.dll")]
        private static extern IntPtr OpenProcess(int flags, bool fInherit, int PID);
        private const int PROCESS_TERMINATE = 1;
        [DllImport("coredll.dll")]
        private static extern bool TerminateProcess(IntPtr hProcess, uint ExitCode);
        [DllImport("coredll.dll")]
        private static extern bool CloseHandle(IntPtr handle);
        private const int INVALID_HANDLE_VALUE = -1; 

        #endregion
    }
}